Project Abstract With nearly 15 million cancer survivors in the United States (U.S.), survivorship care is a growing concern. The aging population, early cancer detection, and improved therapies have all contributed to the increase in cancer survivorship. Cancer survivors have specific health care needs related to late complications of treatment, risk for cancer recurrence, and mental health impact. There is significant variation in the extent to which cancer specialists and primary care providers manage care for cancer survivors and coordinate with each other. These factors can lead to gaps in care, which can in turn lead to adverse outcomes. Safety-net health care systems, which care for low-income and vulnerable populations, face challenges in providing optimal cancer survivorship care due to severe and ongoing resource constraints, including a shortage of subspecialty care and a lack of health information technology (HIT) infrastructure. This application proposes a 5-year career development plan in patient-oriented research for the candidate to expand her mentoring work with early career researchers focused on cancer survivorship care in safety net settings serving diverse populations. In alignment with mentoring plans, the proposal outlines three specific research aims: 1) Characterize the underlying causes of missed monitoring using root cause analysis; 2) Investigate the role of survivorship care plans for diverse patients living with colorectal, prostate, and breast cancers; and 3) Employ implementation science methods to gather stakeholder input on challenges in post-treatment/ survivorship care for diverse patients treated in safety-net settings across California and initiate development of a health information technology-enabled care coordination tool. This proposal will leverage existing federally-funded resources to enhance mentoring in patient-oriented research in cancer survivorship disparities and implementation sciences. Findings from this proposal will lay the groundwork to provide optimal care for all cancer survivors, including those at risk for health disparities and those cared for in resource-constrained safety-net health systems.